Transmitter.



H. GERNSBAGK.

- TRANSMITTER.

APPLICATION FILED MAY16,1913.

Patented Jan. 12, 1915.

WITNESSES 1 STA EFT airmen.

means.

Specification of Letters Patent.

Patented Jan. f2, 1915.

Application filed May 15, 1913. Serial No. 767,888.

To all whom it may ooncem Be itknown that I, Hnco GERNsBAcK, a citizenof the United States, residing at New York, in the county of New Yorkand State of New York, have invented certain new and useful Improvementsin Transmitters, of which the following is a specification, referencebeing had therein to the accompanying drawing.

This invention relates to transmitters and has for its object theproduction of a simple and eflicient transmitter which may bemanufactured at a minimum cost and which may be readily attached to atelephone without the necessity of binding screws and the like as now incommon use.

Another object of this invention is the production of a simple andeflicient transmitter which may be held upon the mouthpiece of atelephone in a vertical position.

With these and other objects in view, this invention consists of certainnovel constructions, combinations and arrangements of parts, as will behereinafter fully described and claimed.

In the drawings :Figure 1 is a vertical sectional view through themouth-piece-casing of the telephone showing the transmitter inelevation. Fig. 2 is a central vertical section through the transmitter.Fig. 3 is a section taken on line 33 of Fig. 2 of the transmitter. Fig.4 is a modified form of the invention. Fig. 5 is a detail perspective ofthe supporting ring for the transmitter. Fig. 6 is a top plan view ofthe transmitter.

By referring to the drawings, it will be seen that 1 designates themouth-piece casing or transmitter casing which carries the usualmouth-piece 2, and this mouth-piece is secured to a cap 2 which isthreaded upon the mouth-piece or transmitter casing, as illustrated inFigs. 1, 2 and 4, and a transmitter supporting disk 3 engages the rearface of this insulated cap 2.

An insulated ring 5 is secured to the rear face of the supporting disk 3as illustrated in Fig. 2 by means of glue or shellac. It is preferableto shellac the insulated ring 5 to the disk 3 so as to allow the same tobe readily removed when it is so desired. It will be seen that .it isnot necessary to have any binding or.securing screws for the disk asillustrated in the present invention, thereby reducing materially in thecost of installation. This insulated ring 5 may be formed of anyinsulated material but is preferably formed of fiber or felt.

A diaphragm disk 6'is secured to the rear face of the supporting disk 3and is held upon this disk by means of theinsulated ring 5 and thebinding insulating ring 7. This insulating ring 7 may, like the ring 5,be formed of any desired insulating material but fiber or felt arepreferable. This diaphragm disk 6 is preferably formed of copper foilwhich is preferably tinned and may be as thin or thinner than No. 40 B.&

S. gage, although if it be so desired the dia;

phragm .disk 6 may be formed of brass of a. thickness of No. 36 B. & S.gage. By having the insulating ring 7 formed of felt, the felt willmaterially deaden the extra vibrations ofthe rim of the diaphragm andfor this reason I preferably employ felt in connection with this ring 7It is, of course, necessary that the diaphragm 6 should be in metallicconnection with the supporting disk 3 which disk 3 is used as one of theconnections of the transmitter.

'A rear plate or disk 8 of substantially three times the thickness ofthe diaphragm 6 or as heavy as the ring or disk 3 is shellacked to therear face of the ring 5 and thereby constitutes a rear closure for thetransmitter. After the glue or shellac which may be used has dried thetransmitter will constitute a substantially one-piece structure.

Within the space between the diaphragm disk 6 and the disk or plate 8there is placed carbon grains 9 for the purpose of constituting anefficient conductor'or transmitter. The grains 9 should not fill thechamber 10 too full for if the grains completely fill the chamber 10, itwill not be able to produce an efiicient transmission. From practicalexperience it has been found that it is advisable to fill the chamber 10about seveneighths full in order to make the clearest speech, and itshould be understood that the plates 3 and 9 will constitute therespective poles of the transmitter.-

By' use of the present device, it will be seenthat the transmitter maybe held in a vertical position and it will not be necessary to have thetransmitter lie in a horizontal position as is now previously done, andin the present device it has been found that the invention operates moreperfectly when in a vertical position than if the same were in ahorizontal position. v

The disk 3 is formed of very rigid material so as to prevent the samefrom vibrating and constitutes an efficient base or support for thevibrating or transmitting disk or diaphragm 6. The plate 8 is alsoformed of heavy material so as to prevent the same from vibrating andthese plates will constitute eflic'ient closures for the transmitter. Itshould be understood that the plates 8 and 3 may be made of any suitablemetal, carbon, or other material, and it is not desired to limit thepresent invention to the particular material above named.

As illustrated in Fig. 4 there is shown a modified form of the inventionwherein a supporting disk 3 is formed similar to that as illustrated inFig. 2 and to this disk is shellacked or glued an insulating ring ordisk 11-which is provided with a lower beveled face 12 and this beveledface 12 is engaged by a spring metal ring 18 for holding the diaphragmit in a firm position against the non-vibrating disk 3.

To the rear face of the insulating ring 11 is secured a plate 15 bymeans of shellac, glue, or other substance, shellac being preierred, andthe disk or ring 11 is preferably formedoi felt or fiber as abovedescribed, but any suitable insulated means may be used. The compartment15 is filled with carbon grains 16 similar to that illustrated in Fig.2, and the compartment is preferably filled seven-eighths full so as tokeep the grain loose and permit an eihcient transmission of the sound.

From the foregoing description, it will be seen that a very simple andeliicient trans mitter has been roducedwherei-nthe parts may be formedof material so as to make the device very cheap in construction and alsoto allow the easy assembling of the several parts upon the disk 3, andin view of the fact that binding screws or the like are not necessary inthe present device, it will be noticed that considerable labor will beeliminated in installing the transmitter upon the telephone.

()fcourse, it should be understood that the present device may be usedand is intended to be used in connection with the ordinary telephone andif builton a larger scale, by making the diameter of the grain chambervastly larger than in an ordinary transmitter, the'device becomesespecially efi'ective when used in connection with transmitters forwireless telephony. In transmitters used at present in wirelesstelephony only a very small grain chamber'is provided which heats upvery quickly when large currents are used. In my transmitter to thecontrary is adapted to support the receiver and constitute a receiverhook, and this transmitter casing 1 may be provided witha contact member19 for engaging the rear face of the disk 8 and constitute an electricalconnection therefor. The receiver hook 18 is provided with a downwardlyprojecting fing'er 20 which is adapted to form a contact with thecontact member 21.

7 It should be understood from the forms illustrated in Figs. 2 and ithat the contact with the disk 3 is made through the contacting member17 as illustrated in the above mentioned figures, and the contact withthe disk 8 and 15 in Figs. 2 and 4: respectively is formed through thecontact member 22.

Having thus described the invention, what I is claimed as new is 2-- Atransmitter of the class described comprising a non-vibrating supportingdisk, an insulating member secured to the rear face of saidnon-vibrating plate by means of adhesive material, a vibrating diaphragmsecuredto the rear face of said non-vibrating plate, a second bindinginsulating member positioned within said first mentioned insulatingmember and engaging said diaphragm, a second non-vibrating plate securedto the opposite face of said insulating members, and spaced from saiddiaphragm disk, and carbon grains loosely placed between said secondmentioned non-vibrating plate and said diaphragm disk.

In testimon whereof l hereunto afiix m 110 signature in presence of twowitnesses.

HUGQ GERNSBACK. Witnesses HAmzr W. Snoon, 'lnnononn L. 'DIEBOLD.

